Climate Change Causes Diseases in Marine Mammals in the Arctic

With fewer days below freezing in the arctic, marine mammals such as gray seals, ringed seals, and beluga whales are increasingly experiencing problems. The latest issue for the creatures has been the emergence of the disease Sarcocystis pinnipedi in the Arctic waters.

The disease has been infecting gray seals, killing 406 of them in Nova Scotia back in 2012. S. pinnipedi has a greater chance of thriving in the warmer Arctic waters. And since the warmer waters are forcing fish such as cod and capelin farther north, the gray seals have to travel to find food. This traveling is allowing the gray seals to come into contact with ringed seals, thus further spreading the disease.

Sarcocytis pinnipedi acts as a cancer in the gray seals. The parasite has been found to replicate in the gray seals' liver until it destroys the organ. Initial examinations of the dead seals did not reveal any telltale signs, but autopsies revealed a failed liver. Researchers from the American Association for the Advancement of Science have reported that the parasite has killed off 20% of gray seals on a single island.

"Climate change is an unprecedented opportunity for pathogens to shift to new environments and cause new diseases," said Michael Grigg, chief of molecular parasitology at the National Institute of Allergy and Infectious Diseases, in this National Geographic article.

The changing environment has also contributed to the rising presence of toxoplasma gondii, which has recently been found to affect beluga whales. It has been found for the first time in the Beaufort Sea. The only ways to kill the disease is the boil it or freeze it, but with less freezing days in these waters it has been able to survive.

Scientists hope to find more information about these parasites through the collection of seal and whale feces. They are also looking at feces of polar bears, the seals' predators. They believe that there is no way to halt these parasites, and that the marine populations will take years to develop any type of immunities.

To read more about the affects these parasites have on marine populations in the Arctic, visit this National Geographic article.